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	hartrees
Energy at 0K	-153.335970
Energy at 298.15K	-153.335075
HF Energy	-153.335970
Nuclear repulsion energy	76.884091

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3407	3368	0.00
2	Σ_g	2219	2194	0.00
3	Σ_g	912	902	0.00
4	Σ_u	3409	3370	198.22
5	Σ_u	2047	2024	4.65
6	Π_g	604	597	0.00
6	Π_g	604	597	0.00
7	Π_g	513	507	0.00
7	Π_g	513	507	0.00
8	Π_u	612	605	97.90
8	Π_u	612	605	97.90
9	Π_u	231	229	7.87
9	Π_u	231	229	7.87

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.680
C2	0.000	0.000	-0.680
C3	0.000	0.000	1.899
C4	0.000	0.000	-1.899
H5	0.000	0.000	2.970
H6	0.000	0.000	-2.970

	C1	C2	C3	C4	H5	H6
C1		1.3603	1.2191	2.5794	2.2895	3.6498
C2	1.3603		2.5794	1.2191	3.6498	2.2895
C3	1.2191	2.5794		3.7985	1.0704	4.8689
C4	2.5794	1.2191	3.7985		4.8689	1.0704
H5	2.2895	3.6498	1.0704	4.8689		5.9393
H6	3.6498	2.2895	4.8689	1.0704	5.9393

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	180.000		C1	C3	H5	180.000
C2	C1	C3	180.000		C2	C4	H6	180.000

All results from a given calculation for C₄H₂ (Diacetylene)

using model chemistry: PBEPBEultrafine/TZVP

States and conformations

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Number	Element	Mulliken
1	C	-0.019
2	C	-0.019
3	C	-0.148
4	C	-0.148
5	H	0.168
6	H	0.168

<r²>	79.251
(<r²>)^1/2	8.902

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBEPBEultrafine/TZVP

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)